How to write HelloWorld program in kotlin-Chapter-3

In the previous blog, I wrote about val and var use and their differences. In this post, I am going to introduce you to the basic steps to write a program in Android with Kotlin. Just follow the simple steps below:-

1)First, declare a string type variable. You can either use val or var for initializing your variable and keep in mind that if you are reinitializing a variable do not use val. write a simple line :-

                                
                               <TextView
                                 android:id="@+id/textView"
                                 android:layout_width="wrap_content"
                                 android:layout_height="wrap_content"
                                 app:layout_constraintBottom_toBottomOf="parent"
                                 app:layout_constraintLeft_toLeftOf="parent"
                                 app:layout_constraintRight_toRightOf="parent"
                                 app:layout_constraintTop_toTopOf="parent" />

3)In the MainActivity.kt. we will initialize a textview using findViewById method like below:-

 var textview=findViewById(R.id.textView) as TextView

4)In the last, you have to assign string value inside textview using text function.

 textview.text=str

5)You are done. Now just run your program. Below is a full code snippet for you to see.

  package adapter.manasvi.com.simpleproject
  import android.os.Bundle
  import android.widget.TextView
  import androidx.appcompat.app.AppCompatActivity

  class HelloWorld : AppCompatActivity() {
      val str:String="Hello World"
      override fun onCreate(savedInstanceState: Bundle?) {
          super.onCreate(savedInstanceState)
          setContentView(R.layout.activity_main)
          var textview=findViewById(R.id.textView) as TextView
          textview.text=str
      }
   }

You will get an Output as “Hello World”.

Feel free to try this code and comment below.